EP 2 032 073 A discloses an implantable medical device comprising a tissue repair material having two sides (faces) and an outer perimeter (periphery) with at least one side adapted for ingrowth of cells. A cuff is formed from the outer perimeter to overlap onto a side of the tissue repair material, creating an opening between the cuff and the tissue repair material. The cuff forms a fixation area at the outer edge of the device for use in joining the device to tissues of a patient.
US 2008/0147099 A shows a bi-layer patch device for hernia repair including a first layer and a second layer. The first layer is cut to form locating flakes. The edges of the first layer and the second layer are connected to form a pocket. The second layer further comprises an auxiliary layer. The patch can be attached to a cavity of the peritoneum for repairing a hernia.
US 2011/0118851 A discloses an implantable prosthesis for repairing or augmenting anatomical weaknesses or defects, and is particularly suitable for the repair of soft tissue and muscle wall openings. The prosthesis includes a repair fabric that is constructed and arranged to allow tissue ingrowth and is susceptible to erosion and the formation of adhesions with tissue and organs. One or more regions of the prosthesis may be configured to inhibit erosion and/or the formation of adhesions. The prosthesis may include an erosion-resistant edge, which can be provided along an opening that is adapted to receive a tube-like structure, such as the esophagus.
Pocket-shaped implants which are currently available on the market show some disadvantages. The pockets are formed by placing various material layers on top of each other, followed by, for example, a seam connection at the edges. Sometimes, support rings are included as well in the edge areas. Implant fixation is only permitted inside these edge connections. This leads to non-fixated edge material which may result in bulged and/or folded edge areas. Furthermore, stiff materials, for example support rings, tend to fail (by bending or breaking). Problems concerning tissue ingrowth as well as organ irritations or injuries can result from the above-mentioned disadvantages. As a consequence of the assembling process (positioning of different material layers on top of each other), the outer edges of some pocket-shaped implants are not covered with anti-adhesive materials and pose a potential risk for adhesions.
Nowadays, the fixation of such pocket-shaped implants is often performed with staplers or tackers. Due to the shape of the current open IPOM (Intra-Peritoneal Onlay-Mesh technique) devices (oval, circular or rectangular with significantly rounded edges), predefined positions of the first fixation points cannot be found.
Furthermore, a correct placement in terms of orientation and centering of the implant after insertion into the abdominal cavity is often difficult.
WO 2011/159700 A describes a composite implant which can be used for repairing hernias, especially incisional hernias, particularly for intraperitoneal applications. This implant includes an alignment marker, which is asymmetric and Is adapted to show the center of the implant and the preferred placement direction for the implant.
WO 2003/037215 A discloses an areal implant having a mesh-like basic structure and a marking in a central region that indicates the center of the implant. A marking line runs through the central marking. The central marking and the marking line can be used for aligning the implant over a surgical opening for reinforcing the tissue.
These implants may give an indication on the orientation of the implant. However, they do not clearly inform the surgeon on the actual position of the periphery of the implant, which might be concealed by bodily tissue. Such information is important because, generally, the implant is fixed to bodily tissue in its peripheral area.